Random lasing emission from WO3 particles dispersed in Rhodamine 6G solution

We experimentally investigate the random lasing emission from tungsten oxide (WO3) particles dispersed in Rhodamine 6G solution. Due to the growing interest in tungsten oxide materials and also their importance and applications in gas sensors, electrochromic and optochromic materials, photoelectrodes and other optoelectrical devices, we choose this material as the scattering elements in a random laser system. Up to our knowledge, the use of WO3 materials as the scattering elements in a random laser system has not yet been reported. WO3 particles provide optical feedback by multiple light scattering. Optical gain is provided by Rhodamine 6G solution through stimulated emission process. Our results show that by adding WO3 particles to Rhodamine 6G solution, single peak random lasing emission is achieved. Furthermore, we investigate the effects of changing the concentration of WO3 particles on the random lasing characteristics. Our results confirm that the increase of WO3 particles leads to the decrease of random lasing threshold, blue-shift of the emission peak, enhancement of the laser emission peak and decrease of its line-width. Due to electrochromic and gasochromic properties of WO3 nanostructures this work can open an avenue for design and fabrication of new tunable and controllable random lasers.